Imperator Caesar Marcus Aurelius Antoninus Augustus (121 - 180 AD) was Roman Emperor from 161 to his death. He was the last of the Five Good Emperors, who governed the Roman Empire from 96 to 180. He was able to secure the succession for his son Commodus, whom he made co-emperor in his own lifetime (in 177), though many historians believe that the decline of Rome began under Commodus. Marcus Aurelius was also one of the most important Stoic philosophers. While on campaign between 170 and 180, Aurelius wrote his Meditations as a source for his own guidance and self-improvement. He had been a priest at the sacrificial altars of Roman service and was an eager patriot. He had a logical mind though his notes were representative of Stoic philosophy and spirituality. Meditations is still revered as a literary monument to a government of service and duty.